16.7 Peptides from Frog Skin
353
on mice (Conlon et al. 2018). Furthermore, recent studies have also shown that
the bioactivity of peptides from frog skin also extends to antimicrobial activity.
Peptides from frog skin have the ability to kill a range of human influenza virus strains
(Crowe 2017). However, these were based on studies carried out at the cellular level.
Peptides from the skin of frog also have potential to serve as antioxidant agents as
recent studies point to antioxidant activity in particular peptide called the antioxidant
peptide, antioxidant-I. These antioxidant proteins which were obtained from the
skin of the Physalaemus nattereri frog have also been shown to possess antioxidant
activity (Barbosa et al. 2018). This peptide also shows the ability to improve the
protective response to hypoxia (low oxygen levels). Other bioactivities which have
been recently detected in frog skin peptides include activity against cystic fibrosis
and cystic fibrosis-related MRSA (methicillin-resistant S. aureus) (Yuan et al. 2019).
Frog skins have been designed to protect the organism from external factors such
as temperature, moisture, UV light, pathogenic microbes and mechanical stress.
Much of these properties can be attributed to proteins present in the skin secretions
which serve this purpose. Although some live on land, frogs spend a substantial part
of their life in or around water, particularly at the tadpole stage, and therefore, they
are considered here as aquatic inhabitants.
Other polysaccharides present in aquatic plants include glucoronan present as
minor polysaccharides in sea lettuce (Kim et al. 2011; Lahaye and Robic 2007),
Rhamnus, arabinogalactans and mannans which are produced by green algae strains
Monostroma and Codium (Tabarsa et al. 2012; Kim et al. 2011; Li et al. 2015).
Cyanobacterium, the only known photosynthesizing eukaryotes, produces glycogen,
a storage carbohydrate (Chao and Bowen 1971; Yoo et al. 2007). Laminarin and
mannitol produced by brown algae have been explored for fermentation ethanol
production, and the microbes for such have been identified by Horn et al. (2000a, b).
16.8 Conclusion
Most of the polymers discussed in this section are either present in less abundance
to those that have been discussed in dedicated chapters in this book or they have
generated less commercial or research interest. Nonetheless, these contribute to the
diversity of biopolymers in the aquatic ecosystem. Even the polymers present in
small traces are of importance as they aid in expanding knowledge on the origins of
certain organisms.
353
on mice (Conlon et al. 2018). Furthermore, recent studies have also shown that
the bioactivity of peptides from frog skin also extends to antimicrobial activity.
Peptides from frog skin have the ability to kill a range of human influenza virus strains
(Crowe 2017). However, these were based on studies carried out at the cellular level.
Peptides from the skin of frog also have potential to serve as antioxidant agents as
recent studies point to antioxidant activity in particular peptide called the antioxidant
peptide, antioxidant-I. These antioxidant proteins which were obtained from the
skin of the Physalaemus nattereri frog have also been shown to possess antioxidant
activity (Barbosa et al. 2018). This peptide also shows the ability to improve the
protective response to hypoxia (low oxygen levels). Other bioactivities which have
been recently detected in frog skin peptides include activity against cystic fibrosis
and cystic fibrosis-related MRSA (methicillin-resistant S. aureus) (Yuan et al. 2019).
Frog skins have been designed to protect the organism from external factors such
as temperature, moisture, UV light, pathogenic microbes and mechanical stress.
Much of these properties can be attributed to proteins present in the skin secretions
which serve this purpose. Although some live on land, frogs spend a substantial part
of their life in or around water, particularly at the tadpole stage, and therefore, they
are considered here as aquatic inhabitants.
Other polysaccharides present in aquatic plants include glucoronan present as
minor polysaccharides in sea lettuce (Kim et al. 2011; Lahaye and Robic 2007),
Rhamnus, arabinogalactans and mannans which are produced by green algae strains
Monostroma and Codium (Tabarsa et al. 2012; Kim et al. 2011; Li et al. 2015).
Cyanobacterium, the only known photosynthesizing eukaryotes, produces glycogen,
a storage carbohydrate (Chao and Bowen 1971; Yoo et al. 2007). Laminarin and
mannitol produced by brown algae have been explored for fermentation ethanol
production, and the microbes for such have been identified by Horn et al. (2000a, b).
16.8 Conclusion
Most of the polymers discussed in this section are either present in less abundance
to those that have been discussed in dedicated chapters in this book or they have
generated less commercial or research interest. Nonetheless, these contribute to the
diversity of biopolymers in the aquatic ecosystem. Even the polymers present in
small traces are of importance as they aid in expanding knowledge on the origins of
certain organisms.